Heater for oil tanks



Dec. 27, 1932. A. G. P. ZERWER HEATER FOR OIL TANKS Filed Oct. 10. 1931 77 #1972 X b 7 yi/mn Patented Dec. 27, 1932 UNITED STATES PATENT OFFICE ADAM G. P. ZERWER, OF WRITING, INDIANA, ASSIGNOR OF ONE-FIFTfi T0 JOHN H. FETTERHOFF AND ONE-FIFTH TO GEORGE J. ZERWER, BOTH OF WHITING, INDIANA HEATER FOB OIL TANKS Application filed October 10, 1931.

These improvements relate to heaters for large-capacity oil tanks used for storing oil for withdrawal from time to time, as for loading same into tank cars, such oil may be of any of the various grades.

The occasion for a heater in such a tank is that the oils of the kinds involved become thick, highly viscous and sometimes scarcely even semifluid in cold weather. Paraflin-base oils will sometimes become almost solid. The tanks are located chiefly out of doors. During the winter it will be impossible to pump oil from such tanks without heating it anywhere from say forty to eighty degrees above the temperature to which it has been reduced by the cold weather.

Although several devices somewhat along the lines of the present one have been suggested heretofore as means for pro-heating the oil for pumping, the interested companies are still adhering to their old methods of heating up large bodies, and substantially the entire body, of the oil within the tank, as by means of steam coils distributed over substantially the entire bottom area of the tank, and maintaining heat in the tank practically all the time, day and night, throughout the cold season. This is not only expensive but it has various other disadvantages among which I may mention that since certain of the oil is thus maintained for a substantially long time in contact with these highly heated pipes the oil is discolored at these places-an objection quite important in the case of the lighter oils.

The present improvements contemplate that heat shall be employed only at the time it is desired to withdraw oil from the tank, thus effecting a notable saving and avoiding other objections to the old method.

A feature of the invention is the provision of means whereby approximately only such a relatively small body of oil is being heated at a given time as is necessary to supply the demands of the exhaust pump freely and easily. To this end I provide a substantially longand narrow tube or shell through which the oil travels, with a heating'unit preferably extending continuously from end to end of the device, and preferably extending some- Serial No. 568,039.

what beyond the open end, whereby a substantially small body of oil in cross-sectional view is in a desirably close association with the heating unit at any given place in the course of travel, the construction thus providin g that a stream of oil flows through the shell with a fairly rapid movement and is thereby heated to the desired fluidity without being maintained obj ectionably long in direct association with the heat.

Other novel features of advantage are in the construction of the device whereby it may be applied for use in a simple, easy, cheap and expeditious way and, in the preferred application, with only a few small holes made in the tank. Other objects and advantages will appear hereinafter.

In the drawing Figure 1 is a fragmentary sectional view of the tank with an embodiment of the present invention shown therein with the shell in vertical longitudinal section, the heating device being in side elevation and the construction being broken away interiorly;

Figs. 2 and 3 are enlarged views showing the heating unit in top plan and side elevation respectively, interior parts which are mere continuations of those shown being broken away;

Fig. 4 is an end view of the device on the section line 4-4 of Fig. 1; and

Fig. 5 is a sectional view as on the line 55 of Fig. 1. i

The views of Figs. 4 and 5 show appropriate proportions of the steam pipes to the shell. In these two figures the shell may be considered to be eight inches in diameter and the steam pipes severally of two inch diameter. Fig. 1, chiefly for the sake of clearness of illustration, does not follow the relative sizes of parts in cross view which I consider most appropriate under the more usual conditions, namely approximately those of Figs. 4 and 5. My object is to cause a stream of the oil, in a substantially small body at any given place, to passwith good movement in close association with the heating unit. The action of the shell is to confine the stream to such close associat on with the heating unit as to bring about the thorough heating of the oil in passage and at the same time to require that it stream fairly rapidly over the heating unit under the action of the pump. Given this principle and mode of operation it will be evident that the propor-' tions and relationship of the parts may vary according to factors found in or for a given installation.

The storage tank fragmentarily shown has a bottom wall 10 and what may be considered a circular s'de wall 11 formed in the usual way. It may be for example forty feet high and sixty feet in diameter.

The heating device comprises the shell 15 and the heating unit marked as a whole 16. The shell may be made of sheet metal such as galvanized or uncoated iron in sections put together according to ordinary tinsmith operations. The shell will ordinarily be cylindrical, and will vary in length from say ten feet for the lighter oils to twenty-five feet or more for the heavier oils. With the shell about eight inches in diameter and about ten feet long it would have a capacity of less than a barrel, and'the presence of the heating unit would reduce that capacity so cons derably that the actual capacity of the shell would be in the neighborhood of twenty-five gallons.

At what I shall call the inner end of the shell is a discharge pipe comprising a pipe element 18 shown as being connected to a nipple 19 strongly secured to the shell as by welding. A union 20 connects pipe section 18 with pipe section 21 wh ch extends through the tank wall and which may be sccured thereto as by welding.

Between section 21 and section 22 is a flanged and packed coupling 23 with bolts holding the two coupling members together. Some kind of a pipe section as 21 for pumping oil out of the tank is nvariably present and may be employed in connection with the present device on its being connected up to a discharge element as 18 or the nipple 19. Owing to the desirability of being able to install the present device s'mply and easily it may be convenient to remove the old outlet pipe and insert onehaving a coupling such as 20 inside the tank.

The coupling elements shown at 23 are threaded upon the pipe sections 21 and 22 respectively and are not present when pipe 21 is secured in place, which is preferably done by welding at 24, making for a strong, firm and perfectly tight joint with the tank wall and which may not leak and which will not require packing. It is to be understood that a pump is connected to pipe section 22 for withdrawing the oil.

The elongated heating unit marked as a whole 16 is preferably of steam piping, although other kinds of heating units may be employed. The one illustrated shows an intake pipe section 25 having a return bend at 26 and a return section 27, the sections 25 It is not necessary that the end wall 29 fit tightly or that the pipes 25 and 27 occupy their respective openings closely, and ordinarily a little looseness there is preferable to permit easy assembly. Leakage into the shell at the end wall 29 would not be objectionable as it would be small in amount and the presence of the steam pipes between the tank wall and the shell and wall heats up the oil in that locality, and some of it may appropriately be drawn into the shell to avoid the objection of undue heating of even that small body of oil. I have shown the holes 25a and 27a as being large enough to permit a flow to occur around the pipes 250 and 270 where the oil would be heated to the greatest extent, and have also shown several holes 31 (Fig. 4) adapted to permit further circulation of preheated oil into the tank at the end wall 29. If outlet 18 were positioned considerably farther to the left as viewed in' Fig. 1 a considerable inflow could be had at end wall 29, and in some instances the end wall might beomitted.

It will be noted that the return bend at 26 (Fig. 1) is about flush with the open end of the shell. It may extend beyond the shell and in some constructions preferably would so extend in a tank holding the heavier oils or even lighter oils of a'paraliine base. This feature of the extension of the heating unit beyond the shell is shown in connection with an auxiliary or branch pipe heating element shown as a pipe section 34 and a pipe section 35 Fig. 2) extending beyond the open end of t e shell (Fig. 1) and returning by means of a loop 36, the sections 34, 35 and 36 being on horizontal lines and the parts 34 and 35 being parallel to each other and at ninety degrees from pipe sections 25 and 27, as shown in Fig. 5. Auxiliary pipe section 35 is connected by means of an elbow 35a (Fig. 3) to intake pipe 26 by means of a T connection 35?) while auxiliary returning pipe 34 is connected by means of an elbow 34a to pipe section 27 by means of a T connection at 34?) (Fig. 3). Steam entering pipe 250 divides at connection 35?) some thereof going through pipe 25 and returning by pipe 27 to connection 346 .while some passes into pipe 35 and returns by pipe 34 to connection 34?).

The ends of pipe sections 250 and 270 are shown as being threaded in Figs. 2 and 3 to receive unions 36 and 37 one of which is shown sectionally in Fig. 3, the same being of ordinary construction. With the unions removed the end wall 29 may be slipped upon the projecting pipe ends 250 and 270 and secured in place.

These unions 36 and 37 are at the inner ends of pipe sections 40 and 41 (Fig. 1) which project through holes in the side wall 11 of the tank and are held there strongly and firmly as by welding. On these sections 40 and 41 are flanged couplings 42 and 43 respectively and from these couplings extend pipe sections 44 and 45 respectively. The coupling elements of the couplings 42 and 43 are threaded respectively upon the several pipe sections as shown and are bolted together, with packing between them, and are of a wellknown type of connection. These couplings are not present when pipe sections 40 and 41 are extended through the side wall 11 from the inside, and therefore the holes for these pipes 40 and 41 may be just large enough to permit the pipes to extend through them. They may therefore be welded in place in a simple and easy way.

It may be noted that the present device may be installed by simply drilling two small holes in the tank for the steam pipes, and, if preferred, another hole -for the outlet pipe from the shell. The cutting out of a large part of the tank wall is therefore avoided, and, furthermore, a leak-proof o1nt is here made with the tank Wall,not calling for packing at any time.

Steam for heating the unit 16 Wlll enter at pipe 44 and come away at pipe 45. Since all of these pipe sections except the bend 26 are on horizontal lines the danger of in ury by freezing of condensed steam is eliminated, for even if some of the condensation should freeze it would be, at most, only at the bottom of any of these steam pipes within the shell or in loop 36. This is an important feature since it is contemplated that the present device will be used only when oil is pumped away from the tank, and it will therefore remain idle large parts of the time.

' The loop extension 36 beyond the open end of the tank is important in connection with the heavier oils and parafline base oils since it extends freely into the body of the always very sluggish and sometimes almost congealed oil, and heats up a body of that oil preparatory to its entering the shell. The oil within the shell becomes quite fluid in a very brief space of time and pumping may be started almost immediately upon turning on the steam. The withdrawal of oil from within the shell would cause even quite sluggish oil to enter at the open end but such entry is facilitated if the oil be preliminarily heated at the entrance opening. It will be appreciated that with a shell of the substantially small diameter indicated, as say eight inches,

oil travels through the shell with a well-defined movement and it is necessary that the intake to the shell be sufliciently large to supply the requirements of such a movement. No obstructions whatever are placed at the intake or open end of the shell and thus, especially with the preliminary heater 36, the shell is supplied with oil as rapidly as it is pumped out.

The heating unit should be held in its proper position within the shell, and to this end I provide a number of supports marked as a whole 48 and shown in Fig. 5 as to their shape. They are simply pieces of strap iron bent as shown and forming seats at 49, 50 and 51 with feet at 52. The upper pipe 25 in Fig. 5 may be supported by U-shaped clamps as 54, such means also holding the supporting members 48 upon the heating unit in the given relative position.

The device as illustrated is very simple and quite cheap in construction, may employ ordinary steam piping and connections, may be assembled readily in operative position, results in apparently the least possible mutilation of the tank, operatives apparently at the leastpossible expense of steam or other heat, and provides that regardless of the weather conditions or the congealed condition of the tank contents the pumping may be started at any time. The full significance of these advantages wi l appear to those 210- quainted with the conditions of the art and the seriousness of the difficulty of pumping from these tanks under present conditions. Some of the difiiculties inhering in the problem will appear from the fact that it is frequently the practice to have some of these large tanks-the ones being used the most or required for emergency purposesentirely housed in by large sheds, and the entire interiors of these sheds maintained well warmed during the'winter to prevent the congealing of the oil in the tanks beyond the conditions required for pumping.

I contemplate as being included in these improvements all such changes, variations and departures from what is thus specifically illustrated and described as fall within the scope of the appended claims.

I claim:

1. Steam pipe construction for a heater of the character described comprising inlet pipemeans and return pipe means having their main parts extending substantially parallel to each other and joined together at their outer ends to form a loop, and pipe means forming an auxiliary loop having an inlet part and a return part joined together at their outer ends, the inner ends of said auxiliary loop parts being joined in communication with said first-mentioned inlet and return pipe means respectively.

2. The construction of claim 1 hereof in which said loops are in planes substantially at right angles to each other.

3. The construction of claim 1 hereof in which the outlet of said return part is at a lower level than is its associated inlet part and the outlet of the return pipe means 1s at a lower level than that of the associated inlet pi e means.

4. onstruction for an oil heater and tank of the character described comprising an elongated shell entirely within the tank, a heating unit comprising a steam pipe therein. having a lead-in section and a lead-out section extending parallel to each other, a wall closing an end of said shell near the tank wall, means holding said wall for ready removability on said shell, said pipe sections extending through said'wa-ll, said shell being open at its other end.

5. An oil heater of the character described comprising a shell with an opening therein at its outer end for oil to flow into the shell,

. means at the inner end of the shell for withdrawing oil from the shell, and a heating unit in the shell and extending through said opening and beyond the shell.

6. The heater of claim 5 hereof in which said opening is at one end of the shell, and said heating unit comprises steam piping having a return bend beyond said opening.

7. The heater of claim 5 hereof in which said heating unit comprises steam piping having a return bend beyond said opening,

said return bend being on a substantially large arc to form an expansion bend in the piping.

8. The heater of claim 5 hereof in which said heating unit comprises steam piping of not more than four straight sections extending substantially parallel to each other and substantially from one end of the shell to.

the other, said sections being substantially horizontal and in loop form.

ADAM G. P. ZERW'ER. 

